1. Field of the Invention
The present invention relates to a cutting machine for cutting out the contours of characters, symbols, and so on from a sheet.
2. Description of the Related Art
As a conventional cutting machine, there is one disclosed in Japanese patent application No. 2000-173653. This cutting machine is apparatus for cutting out desired contours of characters and symbols from a relatively wide sheet having a given length to obtain a pressure-sensitive adhesive sheet from which the contours of characters and symbols have been cut out or in which the contours are left.
The conventional cutting machine has a dedicated input device connected with the machine with a cable. Using this input device, characters and symbols to be cut out, the font of the characters and symbols, and their sizes and positions are entered. The machine cuts out the contours of the desired characters and symbols based on the entered data.
The conventional cutting machine described above performs a first operation. That is, the machine checks whether there is a sufficient amount of sheet to cut out all characters entered. In particular, if the cutting operation is performed while the remaining amount of sheet is left unchecked, the cutting operation can no longer be continued if the sheet to be cut runs out. The sheet currently being cut is also wasted. For these reasons, the remaining amount of sheet is checked at first. The adopted method of checking the remaining amount of sheet consists of once pulling (feeding) a full amount of sheet necessary for a cutting operation out of a sheet loader and checking if the necessary amount of sheet remains at this time using a sensor.
Secondly, after checking the remaining amount of sheet as described above, the sheet pulled out is entirely returned. Then, the sheet is cut based on entered cutting data.
In some cases, a cutting machine is connected with a terminal such as a personal computer. Data is entered using the personal computer as an input device, and fonts and characters of various designs are cut out. In these cases, the cutting machine receives data (coordinate data) about the motion of the cutter from the personal computer, and performs a cutting operation based on the data. The coordinate data sent from the personal computer to the cutting machine does not always start from the front end of the sheet. Depending on the control software in the personal computer, the cutting may be started from an intermediate position in the sheet.
The conventional cutting machine described above did not take account of the connectivity with the personal computer at first. On the assumption that cutting is started from the front end of a sheet, the sheet is fed out to check the remaining amount of sheet and the sheet is entirely returned. Then, cutting is started. Therefore, one must wait at least for a time taken for the sheet to make one reciprocation from the checking of the remaining amount of sheet up to the beginning of the cutting.
In some kind of machine, data is entered into the conventional cutting machine with using a personal computer as an input device, and symbols and characters of various designs are cut. Also, in this case, the remaining amount of sheet is once pulled out and a check is made. Then, the sheet is returned to its original position. Subsequently, cutting is started based on coordinate data from the personal computer. That is, the sheet is reciprocated fully once and then the sheet is again sent to a desired position, and then the cutting is started. Consequently, time is wasted in feeding the sheet from the checking of the remaining amount of sheet up to the start of the cutting.
The present invention has been made in view of the foregoing. It is an object of the present invention to provide a novel cutting machine that shortens the time from the checking of the remaining amount of sheet to the beginning of cutting, unlike the conventional cutting machine, to thereby shorten the total cutting time.
To solve the foregoing problem, a cutting machine according to the present application includes:
a placement portion on which a sheet is placed so as to be movable longitudinally thereof, the sheet having a given width and a considerable amount of length as compared with the width;
a sheet-driving unit for moving the sheet placed on the placement portion longitudinally;
a detection sensor for detecting whether the sheet placed on the placement portion is present or not;
a cutter unit capable of moving in a direction perpendicular to the direction of movement of the sheet made by the sheet-driving unit; and
a control unit for controlling the sheet-driving unit and the cutter unit,
wherein the cutting machine operates the sheet-driving unit and the cutter unit based on given input data to cut the sheet, and
wherein the cutting machine calculates a length of the sheet necessary to perform a cutting operation based on the input data by means of the control unit, feeds out the sheet by the sheet-driving unit based on results of the calculation, and performs a given cutting operation based on the input data without fully returning the sheet fed out by the driving unit after the cutting machine detects whether the sheet of the necessary length found by the calculation is placed with using the detection sensor.